1. Technical Field
The present invention relates to a method of calculating a movement speed of a receiver, or the like.
2. Related Art
As a positioning system using positioning satellite signals, a GPS (Global Positioning System) is widely known, and is used in a GPS receiver which is embedded in a mobile phone, a car navigation device, or the like. In the GPS, position calculation using information, such as the positions of a plurality of GPS satellites or a pseudo distance to each GPS satellite is performed to obtain the position of the GPS receiver or a clock bias.
In the GPS, under the principle that the reception frequency changes depending on the relative speed of the GPS satellite and the GPS receiver, the movement speed of the GPS receiver can be calculated using the transmission frequency of the GPS satellite signal and the reception frequency in the GPS receiver (for example, JP-A-2010-175426).
As described above, in the GPS, the movement speed of the GPS receiver can be calculated. On the other hand, if the movement speed calculated under the above principle is temporally integrated to calculate the movement distance of the GPS receiver, an experiment has shown that the calculated movement distance tends to become shorter than the actual movement distance of the GPS receiver.
If the movement speed can be correctly calculated, the movement distance of the GPS receiver will be correctly obtained. Nevertheless, in the method of the related art, the condition that the movement distance is not correctly obtained means that the movement speed is not correctly calculated due to any number of factors.